Construction material



7 Dec. 22, 1936 J, BROBACK ET AL 2,065,045

CONSTRUCTION MATERIAL Filed April 25, 1933 JUEL I. BROBACK GEORGE J. MARTIN,

w WMW Patented Dec. 22, 19 36 UNlTED STATES PATENT OFFICE CONSTRUCTION MATERIAL Juel Irvin Broliack, Westfield, and George J.

Martin, Denville, N. J.

Our invention relates to a construction material which may be used as a substitute for ordinary wood.

An important object of the invention is to provide material of the above-mentioned character, which is capable of being cut and shaped by ordinary wood working tools, and is especially suited for the interior trim, partitions, ceilings, walls and floors of buildings, boats, etc.

A further object of the invention is to provide a material of the above-mentioned character, which is fire-proof or fire-retarding to a high degree. I

A further object of the invention is to provide material of the above-mentioned character, which is water-resisting, to a high degree.

A further object of the invention is to provide a material of the above-mentioned character, which may be manufactured cheaply, and will not be materially heavier than ordinary lumber.

Other objects and advantages of the invention will be'apparent during the course of the follow- Flgure2 is a vertical section taken on line 2 2 of Figure 1,

Figure 3-ls an enlarged plan view of a portion of the wire inserted asbestos fabric,

Figure 4 is a similarview of the asbestos fabric,

without the wire inse Figure 5 is a'vertlcal section througha modified form of the invention,

Figure 6 is a similar view through a further modified form of the invention.

In the drawing, wherein for the purpose of illustration are shown embodiments of our invensults are obtained by forming the core of alternate sections or strips of wood II and 12. -The strips ll may be of basswood, and the strips l2 of birch wood. These strips are securely glued together at their edges. The invention is in no 5 sense restricted to the employment of this precise material, nor is the invention necessarily restricted to the laminated character of the core.. The laminated characterof the core, however, aids in preventing warping of the completed 10 board, as when subjected to the action of high heat.

A layer of woven asbestos fabric I4 is placed upon each layer l3. This woven asbestos fabric is radically different in construction, and function, from asbestos paper or felt. Woven asbestos fabric consists of strands of asbestos woven to produce a cloth or fabric. Woven asbestos fabric has superior fire-resisting qualities, superior tensile strength, minimum weight, and effects a per- 20 feet bond between the laminations through the medium of a binder, such as water-proof glue. The strength of the woven asbestos fabric permits the laminations being securely bonded together. The woven asbestos fabric embodies threads or yarns having a high asbestos content. The woven asbestos fabric has an asbestos content of about pure asbestos fibre. The use of thewoven asbestos fabric increases the weight of the final product only about 10%, while impregnated fire-proof wood increases the weight from 25% to 40%,-depending onthe degree of fire-proofness. Asbestos paper contains only about 20% of pure asbestos fibre. Asbestos paper is stratified and has a low tensllelstrength and 35 readily splits or separates into layers, and therefore cannot make a strong bond between the laminations. Asbestos paper also has a lower fire-resistance. The asbestos fabric l4 has its strands l4 provided with wire inserts I4 preferably formed of fine plated brass strands, about which the asbestos yarn is wound. We also contemplate using an asbestos fabric I, Figure 4, wherein the wire I4 is omitted.

The laminations in Figure 1 are shown as applied to both sides of the core ill, but some de-- gree of success may be had by applying them to one side only.

An outer layer I5 is provided, which may be formed of wood veneer, paper, pulp, or other 50 asbestos fabric [4 are coated with this waterproof glue, and the interior surfaces of the outer 1t yers l5 are coated with this water-proof glue.

These superposed layers, when assembled, are

subjectedto a pressure of about 100 pounds per square inch, and the glue is allowed to dry .under this pressure. 'The glue may be applied to the laminations by means of a glue spreader, consisting of two rollers receiving glue thereon, between which the said lamination is run.

While it is preferred to use the cross bands I3.

they may be omitted, as shown in Figure 5, in

which event the woven asbestos fabric will -be directly cemented upon the core-i0. When the word core is used in the claims, without additional limitations, it is intended that this word cover the inner element including the strips ll, without the bands or veneer I3, Figure 5, or an inner element including the strips H and bands or veneer l3.

In Figure 6, we have shown a further modiflca- 1 tion of the invention, wherein the woven asbestos fabric I 4 is employed and is arranged between two strips or sheetslG, and is glued or cemented thereto. These strips orsheets may be formed of wood, paper pulp, or-other fibrous material.

In this formof the invention, the core 10 is omitted.

The water-proof glue which we prefer to use has a glue mineral base, and when dry is a rocklike material which is not only water-proof but fireproof. This glue contains casein,- which is a mineral. The invention is not restricted to the use of this particular type of glue, as other glues or cements may be employed. Further, thelam- .inations may be secured together by means other than glue. They may be nails, screws, or the-like.

A specimen embodying a. preferred embodiment of the invention, as described in Figures 1 secured together by to 4, inclusive, the wire not being present in the asbestos woven fabric, was. subjected" to a. fire test. The flame from an air-gas torch was applied to the walnut-veneered surface, and the effect uponthe specimen recorded in the log of fire test.

The temperature at the point of application of the flame and on the underside of the specimen were recorded with a Leeds and Northrup potentiometer temperature indicator. The tempera ture was raised to 1700 F. in thirty minutes, and

maintained for thirty minutes at 1700 F. At the end of the test the specimen was submerged in water and the effect upon the specimen noted.

The following log of test ed during the test:

gives the data record- Temperature of flame Time mums Remarks Top Under side side F. F. 0 70 Room temperature 70 F. 3 900 70 Wood began charring. Charred area,

diameter=l inch. 7 1040 70 Charred area increasing slowly. No

flaming on removal of flame. 12 1140 74 Chimes area increased to 2 inches diame r. 15 1220 84 Charred area, diameter=2 inches. 17 1240 92 Layer of asbestos becoming exposed. 21 1240 9G 2% 1470 106 .Flaming in spots on removal of flame. 7 Top layer of walnut veneer charred, exposing wbestos layer. 27 1400 117 30....-- 1480 124 Charred area, 3 inches in diameter. 83...... 167 5 134 Veneer flaming slightly on removal 0! I flame. Asbestos glowing under flame,

glow fading on removal of flame. 1730 Charred area, 5 inches in diameter. 1650 1730 Asbestos glowing, but shows no signs of breaking up. 1700 204 1740 262 Charred area, 6 inches in diameter. As-

bestos showing signs of breaking up. No signs of charring on underside. 57- 1700 E0 60 1700 290 Signs of charring and cracking of veneer on under side. No change after application of water.

Although the surface appeared charred it seemed. intact, but the asbestos and wood core was easily scrapedaway indicating oxidation of the material.

After removing charred portion, an opening ,4

inches in diameter was formed, extending through the basswood and birch core, which was charred and cracked. The opening on the underside was about V2 inch in diameter.

Having fully described our invention, what we claim is:

1. A building material comprising layers of fibrous material and a layer of woven asbestos fabric between said layers, said fabric comprising strands having wire inserts, said layers being securely cemented together.

2. A fire resisting buildingboard, comprising a core, said core including strips of wood having their edges cemented together, sheets of wood I veneer cemented to the opposite faces of the core,

' sheets of fire resisting fabric cemented to the outer faces of the sheets of veneer, said .fire resisting fabric including woven metal strands having a. covering of asbestos yarn wound thereon, and sheets of veneer cemented to the outer faces of the fire resisting fabric.

3. A building board comprising a core, sheets of fire resisting fabric arranged upon the opposite faces of the core, said fabric comprising woven wire strands having a covering of asbestos yarn wound thereon, and a water-proof glue containing casein forsecurely binding these elements together and producing a rock-like material when dry which is fire-proof.

- JUEL IRVIN BROBACK.

GEORGE J. MARTIN. 

